Bug 10030: QA Followup for trivial false warning detected while testing

Bug 10030: QA Followup for trivial false warning detected while testing

Moving the warn line below the line that returns if amount<=0.
If amount<=0, a false warn is now raised because of the return after it.
We should only warn here if we do not return.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Tested with fines.pl on overdue.
Before this patch:
Reducing fine for item 199709 borrower 23 from 44 to -1 - MaxFine reached.
This did not happen however because of the return.
After this change: no false warning.
Signed-off-by: Jared Camins-Esakov <jcamins@cpbibliography.com>